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Biomedical subjects

R J Hawley

Publications and source records attributed to R J Hawley.

At least 73 records · Page 4Linked to original sources
PubMed1980

The contribution of assays for lymphocyte capping and creatine kinase to detection of the Becker-type dystrophy trait.

Members of three unrelated families with the mild Becker type of muscular dystrophy were subjected to lymphocyte capping tests and measurements of serum creatine kinase activity. Both tests correctly identified all nine affected males, but only the capping test was abnormal in seven of eight obligate carriers. The number of capped cells in carriers and affected persons with the Becker-type dystrophy was generally intermediate between those observed for individuals with the Duchenne trait and normal controls, thus potentially aiding in the differential diagnosis between the two myopathies. The lack of sensitivity of measurements of serum creatine kinase activity in identifying carriers is further complicated by the difficulty of establishing reliable reference intervals for this enzyme in 204 healthy controls. Detailed directions for the performance of the capping test are presented.

Adolescent↗
PubMed1979

The ultrastructure of bronchial macrophages and lymphocytes in sarcoidosis.

A physical interaction between macrophages and lymphocytes was observed more frequently in bronchial lavage fluid obtained from patients with sarcoidosis than from normal volunteers, irrespective of their history of smoking. In this spontaneous interaction more than two lymphocytes were commonly seen adhering to a macrophage without evidence of cytoplasmic bridging or membrane fusion. To a greater extent than in normal volunteers, macrophages from patients with sarcoidosis were characterized by the appearance of a more highly irregular cell surface, more membrane bound inclusions, however, was positively correlated with the smoking history of the individual, and the number of surface projections (microvilli) of macrophages from smokers appeared to be reduced. Significant differences were not apparent in the nuclear or cellular diameters of macrophages from sarcoid and normal individuals.

Bronchi↗
PubMed1979

Cardiac findings in Charcot-Marie-Tooth disease. A prospective study of 68 patients.

Charcot-Marie-Tooth disease (peroneal muscular atrophy) has been reported to cause cardiac arrthymias and conduction disturbances in association with peripheral muscle atrophy. To establish more accurately the frequency of such cardiac disorders in this disease, 68 patients with Charcot-Marie-Tooth disease were evaluated prospectively for evidence of cardiac involvement. Cardiac findings were limited to five patients with conduction defects, two patients with supraventricular tachycardia, two patients with ischemic heart disease, and 20 with mitral valve prolapse. The frequency of each of the abnormal cardiac findings, with the possibly emalities in the population at large. The low incidence of cardiac involvement in patients with Charcot-Marie-Tooth disease may be helpful in distinguishing this disorder from Friedreich's ataxia, an entity that may mimic Charcot-Marie-Tooth disease but that is frequently associated with heart disease.

Adult↗
PubMed1978

Cardiac manifestations in polymyositis.

Twenty-one patients with polymyositis were prospectively examined with echocardiography, phonocardiography and electrocardiography. Cardiac performance, estimated with echocardiography, was enhanced as shown by a significant (P less than 0.01) increase in ejection phase indexes of left ventricular function compared with values in a matched control group. Known causes of the high output state, such as anemia or thyrotoxicosis, were not clinically evident. There was no evidence of left ventricular enlargement, left ventricular wall hypertrophy, or left atrial enlargement in the echocardiogram or chest X-ray film. The echocardiogram showed systolic mitral valve prolapse in 11 of 17 patients (65 percent) with an adequately imaged mitral valve; midsystolic clicks were present in 7 of these. One patient, who did not have prolapse, had echocardiographic evidence of a small pericardial effusion. Electrocardiographic abnormalities were present in 11 of 21 patients (52 percent) and included evidence of atrioventricular conduction disturbances, atrial and ventricular arrhythmias and left atrial abnormality. The pathophysiology of mitral valve prolapse and increased systolic left ventricular function in polymyositis remains uncertain; however, the spectrum of cardiac abnormalities, detected noninvasively in 16 of 21 of our patients (76 percent) may represent a high frequency rate of cardiac involvement in this disease.

Adult↗
PubMed1978

"Conjugal" transfer of plasmid DNA among oral streptococci.

The beta plasmid from Streptococcus faecalis strain DS5, which codes for resistance to erythromycin and lincomycin, was introduced into a Lancefield group F streptococcus, strain DR1501, by transformation. This strain, DR1501 (beta), was found to be an excellent donor of the beta plasmid and readily transferred the resistance markers to various lactic acid bacteria, including certain strains of S. mutans, S. sanguis, and S. salivarius. Evidence is presented indicating that the transfer of the beta plasmid is mediated by a mechanism that requires cell-to-cell contact. The transfer of plasmid DNA during conjugation has been confirmed by the isolation of beta plasmid from transconjugant clones and by their ability to then serve as donors of the erythromycin and lincomycin resistance markers.

Conjugation, Genetic↗
PubMed1977

Focal lesions of muscle in peripheral vascular disease.

Lesions in skeletal muscle resulting from ischemia caused by peripheral vascular disease in two patients were essentially identical to the early muscle lesions of Duchenne muscular dystrophy (DMD) patients and carriers of that disease, as well as to the early muscle lesions of experimental animals with aorta ligations plus a small dose of 5-hydroxytryptamine (serotonin). The one similarity is harmonious with, although does not necessarily advance, the ischemia hypothesis of DMD, and the other supports the ischemia mechanism proposed in the animal model.

Adult↗
PubMed1977

Ultrastructure of Nocardia-like variants of Mycobacterium smegmatis and chemical composition of the basal cell wall layer.

Mycobacterium smegmatis, its orange-red--pigmented (OR) variants, and back mutant strains were examined by electron microscopy using ultrathin sectioning, negative or positive staining, and freeze-fracture-etching methods. The parental and back mutant strains showed almost identical ultrastructures. Specifically, thick ramified fibers measuring about 15 nm in diameter were always visible in the positively stained cell wall, although they were not readily visualized with negative staining or freeze-fracture-etching. In contrast, the cell walls of OR variants contained fibrous networks measuring about 11 nm in diameter, which could be observed by positive and negative staining as well as freeze-fracture-etching. Although cytoplasmic structures appeared similar among the four strains examined, mesosomes were significantly more abundant in the OR variants. The basal layer of the cell wall obtained as a phenol residue consisted of a dense membranous matrix containing scattered fibrous structures in the parental and back mutant strains, and fibrous networks in the OR variants. Chemical analyses showed that the basal layers of all four strains contained the same neutral sugars, amino sugars, and amino acids, i.e., arabinose, galactose, muramic acid, glucosamine, alanine, glutamic acid, and diaminopimelic acid. The alpha-branched, beta-hydroxylated fatty acids contained in the basal layers differ among the four strains, however, with nocardomycolic acids being present in the OR variants and mycolic acids in the parental and back mutant strains. Our previous conclusion that OR variants of M. smegmatis have characteristics similar to those of nocardia is supported by the present study.

Amino Acids↗
PubMed1976

Isolation and characterization of nocardia-like variants of Mycobacterium smegmatis.

Orange-red-pigmented (OR) colonies were isolated from cream-yellow-pigmented Mycobacterium smegmatis after exposure to either mycobacteriophage MC4 or ultraviolet light; these variant strains were designated OR4 and ORuv, respectively. Early subculture of OR-colonies did not show any segregation of parental-type cells. However, colonies resembling the parental strains, possibly representing a back mutant (REV-OR4), were occasionally found during subculture of established OR-colonies or upon treatment with N-nitrose-N'-nitro-N-methylguanidine. The OR-variants were characterized by their lytic response to nocardiophage, but not to mycobacteriophages, presence of alpha-branched, beta-hydroxylated fatty acids of the Nocardia-type, and a guanine plus cytosine value of deoxyribonucleic acid (DNA) between 62 and 64 mol%. They were more resistant to the lethal action of both ultraviolet light and mitomycin C treatment than the parental and back mutant strains. Although the OR-variants in this study possess characteristics common to the genus Nocardia or some of the 'rhodochrous' mycobacteria, evidence is presented that they form a new class of mycobacterial variants.

Fatty Acids↗
PubMed1976

An ultrastructural analysis of protoplast-spheroplast induction in Cryptococcus neoformans.

Protoplasts-spheroplasts of a human isolate of Cryptococcus neoformans were prepared using the gut enzyme of Helix pomatia. The induction process, as studied by transmission electron microscopy, occurred in two stages. Early in the induction process, protoplasts-spheroplasts emerged from whole cells through a break in the cell wall-capsule envelope. Later, a gradual dissolution of the entire cell wall occurred releasing the intact protoplast-spheroplast. A comparison of protoplasts-spheroplasts with normal untreated cells revealed that the degree of cellular vacuolation as well as the resolution of cellular organelles was similar.

Cell Wall↗
PubMedDate not supplied

Human brain: aldehyde dehydrogenase activity and isozyme distribution in different areas.

Three human post-mortem brains were dissected into seventeen areas and assayed for aldehyde dehydrogenase (EC 1.2.1.3) activity employing two assay systems: one at 68 microM and another at 13.6 mM propionaldehyde. The levels of activity with 68 microM propionaldehyde were significantly higher in cerebellum and putamen. The same brain areas were also examined by isoelectric focusing. By this procedure two distinct bands of aldehyde dehydrogenase activity (the cytoplasmic E1 and mitochondrial E2) could be readily visualized in cerebellum and putamen while other brain areas contained mainly the mitochondrial E2 isozyme.

Aged↗
PubMedDate not supplied

Trace element levels in human alcoholic brain.

Copper, magnesium, zinc and manganese levels in the temporal cortex of human alcoholic and control brains were measured by atomic absorption spectrophotometry using both the flame and graphite furnace. All of the 21 alcoholics were male with a mean age of 54.1 years; the 19 male controls had a mean age of 60.2 years. The only statistically significant change in ion levels was an increase in manganese concentration (expressed both as microgram/g wet weight and ng/mg protein) in the alcoholic group when compared to the control group. Five of the alcoholics had malignancies, while 16 of the controls had systemic malignancies. Covariance analysis showed there was no effect of age on the level of manganese in the temporal cortex.

Adult↗
PubMedDate not supplied

Elevated cerebrospinal fluid histidine in alcohol withdrawal.

Cerebrospinal fluid (CSF) histidine concentration was significantly elevated in seven patients early in the alcohol withdrawal syndrome (206.3 +/- 74.4 (SEM) nanomols/ml CSF). When these same patients were restudied an average of six days later when alcohol withdrawal was clinically resolved, their mean CSF histidine concentration continued to be significantly elevated (164.7 +/- 24.7) when compared to normal (12.0 +/- 0.5 nanomols/ml CSF). Other amino acids (aspartic acid, serine, alanine, methionine, leucine, tyrosine, phenylalanine, lysine and arginine) showed no definite changes from normal, and no change during the course of alcohol withdrawal. Possible reasons for these high concentrations and the extreme variability (especially early in alcohol withdrawal) are discussed.

Adult↗
PubMedDate not supplied

Potential of aspirin to inhibit thrombotic microangiopathy in alpha1,3-galactosyltransferase gene-knockout pig hearts after transplantation in baboons.

Hearts from alpha1,3-Galactosyltransferase gene-knockout (GaIT-KO) pigs were transplanted heterotopically into 8 baboons that received an anti-CD154 monoclonal antibody (mAb)-based immunosuppressive regimen and heparin. Three baboons died or were euthanized with beating grafts on 16, 23, and 56 days, respectively, and the remaining 5 grafts functioned for 59-179 days. Hyperacute rejection did not occur, and classical features of acute humoral xenograft or acute cellular rejection were rare. However, thrombotic microangiopathy (TM) developed in all cases; its onset was delayed in 2 baboons that received aspirin. Function of a pig organ in a baboon for a period approaching 6 months has not been reported previously and lends encouragement that the barriers to xenotransplantation will be overcome, but TM requires investigation.

Animals↗
PubMedDate not supplied

Brain and liver monoamine oxidase type A and type B activity in alcoholics and controls.

Monoamine oxidase activity in human postmortem brain and liver samples was measured in a group of patients with a prior history of alcoholism and compared to a control group with no prior history of alcoholism. Liver samples from patients with a prior history of alcoholism showed significantly lower monoamine oxidase activity with both phenylethylamine and serotonin as substrates. Postmortem brain samples, however, were not different in the two groups.

Adult↗